An engaging mechanism, a transmission dock equipped with the same, and an electronic apparatus having the same are provided. The engaging mechanism includes a rotary fastening element, a guiding frame and a translating frame. The rotary fastening element rotates about an axis to reach an engaging state. The guiding frame has two opposing outer sidewalls and is protrudingly disposed on a support surface of the transmission dock. The axis is substantially parallel to the support surface. The rotary fastening element protrudes from one of the outer sidewalls in the engaging state. The translating frame has two opposing inner sidewalls and two opposing upper wall surfaces. The two outer sidewalls are disposed between the two inner sidewalls, allowing the rotary fastening element to rotate and reach the engaging state and thereby stop one of the upper wall surfaces, when the translating frame connects with the support surface.